/*
*  RFC 1321 compliant MD5 implementation
*
*  Copyright (C) 2001-2003  Christophe Devine
*
*  This program is free software; you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  This program is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*  GNU General Public License for more details.
*
*  You should have received a copy of the GNU General Public License
*  along with this program; if not, write to the Free Software
*  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <string.h>
#include "md5.h"

#define GET_UINT32( n, b, i )                       \
{                                               \
  (n) = ( (uint32_t) (b)[(i)    ]       )       \
  | ( (uint32_t) (b)[(i) + 1] <<  8 )       \
  | ( (uint32_t) (b)[(i) + 2] << 16 )       \
  | ( (uint32_t) (b)[(i) + 3] << 24 );      \
}

#define PUT_UINT32( n, b, i )                       \
{                                               \
  (b)[(i)    ] = (uint8_t) ( (n)       );       \
  (b)[(i) + 1] = (uint8_t) ( (n) >>  8 );       \
  (b)[(i) + 2] = (uint8_t) ( (n) >> 16 );       \
  (b)[(i) + 3] = (uint8_t) ( (n) >> 24 );       \
}

void Sapphire::Common::Util::md5_starts( md5_context* ctx )
{
  ctx->total[ 0 ] = 0;
  ctx->total[ 1 ] = 0;

  ctx->state[ 0 ] = 0x67452301;
  ctx->state[ 1 ] = 0xEFCDAB89;
  ctx->state[ 2 ] = 0x98BADCFE;
  ctx->state[ 3 ] = 0x10325476;
}

void md5_process( Sapphire::Common::Util::md5_context* ctx, uint8_t data[64] )
{
  uint32_t X[16], A, B, C, D;

  GET_UINT32( X[ 0 ], data, 0 );
  GET_UINT32( X[ 1 ], data, 4 );
  GET_UINT32( X[ 2 ], data, 8 );
  GET_UINT32( X[ 3 ], data, 12 );
  GET_UINT32( X[ 4 ], data, 16 );
  GET_UINT32( X[ 5 ], data, 20 );
  GET_UINT32( X[ 6 ], data, 24 );
  GET_UINT32( X[ 7 ], data, 28 );
  GET_UINT32( X[ 8 ], data, 32 );
  GET_UINT32( X[ 9 ], data, 36 );
  GET_UINT32( X[ 10 ], data, 40 );
  GET_UINT32( X[ 11 ], data, 44 );
  GET_UINT32( X[ 12 ], data, 48 );
  GET_UINT32( X[ 13 ], data, 52 );
  GET_UINT32( X[ 14 ], data, 56 );
  GET_UINT32( X[ 15 ], data, 60 );

#define S( x, n ) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

#define P( a, b, c, d, k, s, t )                                \
  {                                                       \
  a += F(b,c,d) + X[k] + t; a = S(a,s) + b;           \
  }

  A = ctx->state[ 0 ];
  B = ctx->state[ 1 ];
  C = ctx->state[ 2 ];
  D = ctx->state[ 3 ];

#define F( x, y, z ) (z ^ (x & (y ^ z)))

  P( A, B, C, D, 0, 7, 0xD76AA478 );
  P( D, A, B, C, 1, 12, 0xE8C7B756 );
  P( C, D, A, B, 2, 17, 0x242070DB );
  P( B, C, D, A, 3, 22, 0xC1BDCEEE );
  P( A, B, C, D, 4, 7, 0xF57C0FAF );
  P( D, A, B, C, 5, 12, 0x4787C62A );
  P( C, D, A, B, 6, 17, 0xA8304613 );
  P( B, C, D, A, 7, 22, 0xFD469501 );
  P( A, B, C, D, 8, 7, 0x698098D8 );
  P( D, A, B, C, 9, 12, 0x8B44F7AF );
  P( C, D, A, B, 10, 17, 0xFFFF5BB1 );
  P( B, C, D, A, 11, 22, 0x895CD7BE );
  P( A, B, C, D, 12, 7, 0x6B901122 );
  P( D, A, B, C, 13, 12, 0xFD987193 );
  P( C, D, A, B, 14, 17, 0xA679438E );
  P( B, C, D, A, 15, 22, 0x49B40821 );

#undef F

#define F( x, y, z ) (y ^ (z & (x ^ y)))

  P( A, B, C, D, 1, 5, 0xF61E2562 );
  P( D, A, B, C, 6, 9, 0xC040B340 );
  P( C, D, A, B, 11, 14, 0x265E5A51 );
  P( B, C, D, A, 0, 20, 0xE9B6C7AA );
  P( A, B, C, D, 5, 5, 0xD62F105D );
  P( D, A, B, C, 10, 9, 0x02441453 );
  P( C, D, A, B, 15, 14, 0xD8A1E681 );
  P( B, C, D, A, 4, 20, 0xE7D3FBC8 );
  P( A, B, C, D, 9, 5, 0x21E1CDE6 );
  P( D, A, B, C, 14, 9, 0xC33707D6 );
  P( C, D, A, B, 3, 14, 0xF4D50D87 );
  P( B, C, D, A, 8, 20, 0x455A14ED );
  P( A, B, C, D, 13, 5, 0xA9E3E905 );
  P( D, A, B, C, 2, 9, 0xFCEFA3F8 );
  P( C, D, A, B, 7, 14, 0x676F02D9 );
  P( B, C, D, A, 12, 20, 0x8D2A4C8A );

#undef F

#define F( x, y, z ) (x ^ y ^ z)

  P( A, B, C, D, 5, 4, 0xFFFA3942 );
  P( D, A, B, C, 8, 11, 0x8771F681 );
  P( C, D, A, B, 11, 16, 0x6D9D6122 );
  P( B, C, D, A, 14, 23, 0xFDE5380C );
  P( A, B, C, D, 1, 4, 0xA4BEEA44 );
  P( D, A, B, C, 4, 11, 0x4BDECFA9 );
  P( C, D, A, B, 7, 16, 0xF6BB4B60 );
  P( B, C, D, A, 10, 23, 0xBEBFBC70 );
  P( A, B, C, D, 13, 4, 0x289B7EC6 );
  P( D, A, B, C, 0, 11, 0xEAA127FA );
  P( C, D, A, B, 3, 16, 0xD4EF3085 );
  P( B, C, D, A, 6, 23, 0x04881D05 );
  P( A, B, C, D, 9, 4, 0xD9D4D039 );
  P( D, A, B, C, 12, 11, 0xE6DB99E5 );
  P( C, D, A, B, 15, 16, 0x1FA27CF8 );
  P( B, C, D, A, 2, 23, 0xC4AC5665 );

#undef F

#define F( x, y, z ) (y ^ (x | ~z))

  P( A, B, C, D, 0, 6, 0xF4292244 );
  P( D, A, B, C, 7, 10, 0x432AFF97 );
  P( C, D, A, B, 14, 15, 0xAB9423A7 );
  P( B, C, D, A, 5, 21, 0xFC93A039 );
  P( A, B, C, D, 12, 6, 0x655B59C3 );
  P( D, A, B, C, 3, 10, 0x8F0CCC92 );
  P( C, D, A, B, 10, 15, 0xFFEFF47D );
  P( B, C, D, A, 1, 21, 0x85845DD1 );
  P( A, B, C, D, 8, 6, 0x6FA87E4F );
  P( D, A, B, C, 15, 10, 0xFE2CE6E0 );
  P( C, D, A, B, 6, 15, 0xA3014314 );
  P( B, C, D, A, 13, 21, 0x4E0811A1 );
  P( A, B, C, D, 4, 6, 0xF7537E82 );
  P( D, A, B, C, 11, 10, 0xBD3AF235 );
  P( C, D, A, B, 2, 15, 0x2AD7D2BB );
  P( B, C, D, A, 9, 21, 0xEB86D391 );

#undef F

  ctx->state[ 0 ] += A;
  ctx->state[ 1 ] += B;
  ctx->state[ 2 ] += C;
  ctx->state[ 3 ] += D;
}

void Sapphire::Common::Util::md5_update( md5_context* ctx, uint8_t* input, uint32_t length )
{
  uint32_t left, fill;

  if( !length )
    return;

  left = ctx->total[ 0 ] & 0x3F;
  fill = 64 - left;

  ctx->total[ 0 ] += length;
  ctx->total[ 0 ] &= 0xFFFFFFFF;

  if( ctx->total[ 0 ] < length )
    ctx->total[ 1 ]++;

  if( left && length >= fill )
  {
    memcpy( ( void* ) ( ctx->buffer + left ),
            ( void* ) input, fill );
    md5_process( ctx, ctx->buffer );
    length -= fill;
    input += fill;
    left = 0;
  }

  while( length >= 64 )
  {
    md5_process( ctx, input );
    length -= 64;
    input += 64;
  }

  if( length )
  {
    memcpy( ( void* ) ( ctx->buffer + left ),
            ( void* ) input, length );
  }
}

static uint8_t md5_padding[64] =
  {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  };

void Sapphire::Common::Util::md5_finish( md5_context* ctx, uint8_t digest[16] )
{
  uint32_t last, padn;
  uint32_t high, low;
  uint8_t msglen[8];

  high = ( ctx->total[ 0 ] >> 29 )
         | ( ctx->total[ 1 ] << 3 );
  low = ( ctx->total[ 0 ] << 3 );

  PUT_UINT32( low, msglen, 0 );
  PUT_UINT32( high, msglen, 4 );

  last = ctx->total[ 0 ] & 0x3F;
  padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );

  md5_update( ctx, md5_padding, padn );
  md5_update( ctx, msglen, 8 );

  PUT_UINT32( ctx->state[ 0 ], digest, 0 );
  PUT_UINT32( ctx->state[ 1 ], digest, 4 );
  PUT_UINT32( ctx->state[ 2 ], digest, 8 );
  PUT_UINT32( ctx->state[ 3 ], digest, 12 );
}

/*
* those are the standard RFC 1321 test vectors
*/

void Sapphire::Common::Util::md5( uint8_t* text, uint8_t* hash, int32_t size )
{
  md5_context ctx;
  md5_starts( &ctx );
  md5_update( &ctx, ( uint8_t* ) text, size );
  md5_finish( &ctx, hash );
}